More particularly, the invention relates to landing gear for aircraft comprising:                a landing gear strut extending along a main axis of the landing gear;        at least one axle mechanically connected to a first side of the landing gear strut;        at least one wheel rotatably mounted about said at least one axle;        at least one damper arranged to dampen a sliding movement of said landing gear strut relative to the structure of the aircraft.        
The landing gear further comprises at least one pair of first and second parts, said first part having a steel substrate and a sliding layer formed on this substrate, the second part being mounted in sliding contact against said sliding layer with a maximum rectilinear sliding amplitude of this second part against said sliding layer of the first part, strictly less than 0.5 mm, the sliding layer being adapted to support, at least during the sliding, a surface pressure in excess of 50 MPa.
When using the landing gear to support the aircraft and roll it along the ground, significant vibrations in the landing gear occur despite the use of a damper. These vibrations generate a contact wear phenomenon, also known as fretting, on the contact surfaces between the parts.
This fretting phenomenon is particularly pronounced:                when there is a relative sliding amplitude of the parts placed in contact with one another;        when the relative sliding amplitude is low, namely less than 0.5 mm; and        when the surface pressure applied between these contacting parts is high, namely greater than 50 MPa.        
The presence of low amplitude slippage between two parts against one other helps concentrate the wear phenomenon on a small contact area between these parts. This increases the wear effect at depth of the part and thus increases the risk of its corrosion and its cracking. This is especially true for low-alloy steel parts.
This fretting is greater as the frequency of the vibrations transmitted increases during aircraft roll-out.
In order to limit this fretting phenomenon, it is known to form a chrome sliding layer on the steel substrate of the part having a tendency to become worn or wear another part. This layer has the advantage of being a very hard material and fretting-resistant.
It has been noted that the use of chromium is sometimes not satisfactory as microcracks can pass through the chromium layer, reach the substrate and generate corrosion points likely to create incipient cracks detrimental to the mechanical strength of the corroded part.